PURPOSE: In light of the need for new treatment options for patients with previously treated CTCL, the purpose of this multinational, non randomized, phase II study is to assess the efficacy of oral LBH589 as single agent in patients with CTCL whose disease has progressed following or has not responded to at least two prior systemic treatment regimens.

Key Eligibility Criteria: Inclusion
1. Written informed consent obtained prior to any screening procedures
2. Age ≥ 18 years old
3. Patients with biopsy-confirmed mycosis fungoides or Sézary syndrome stages IB-IVA. Patients who have SS with bone marrow involvement are also eligible. Patients with transformed CTCL are eligible. Disease stage for eligibility is based on the stage at time of study enrollment. However, patients with any history of visceral involvement of their CTCL will not be eligible for this study.
4. Patients must have received at least two prior treatment regimens at least one of which was a systemic therapy regimens. Systemic regimens include oral bexarotene, PUVA, photophoresis, oral corticosteroids, total skin electron bean therapy, immunotherapy, chemotherapy such as methotrexate, biological response modifiers such as and interferon. Topical steroids alone are not considered as a treatment regimen.
5. Patients must have had disease progression on or following their most recent treatment regimen. Patients are also eligible if they had an inadequate response to their most recent treatment regimen defined as stable disease as the best response after at least 3 months of therapy.
6. Patients will be accrued to one of two groups:

• Group 1: Patients previously treated with oral bexarotene. This group includes patients who had:

1. Disease progression on following treatment oral bexarotene, OR
2. An inadequate response to oral bexarotene treatment defined as stable disease as the best response after at least 3 months of treatment, OR
3. Intolerance of oral bexoratene defined as patients who discontinued oral bexoratene treatment due to adverse events.
• Group 2: Patients who have not had prior oral bexarotene treatment.

Please contact the study site to see if you meet the other criteria for this study.